The subject matter disclosed herein relates generally to systems and methods for computed tomography (CT) imaging.
In CT imaging, an X-ray source may be rotated around an object to obtain imaging information. X-rays from the source attenuated by the object may be collected or detected by a detector and used to reconstruct an image. Patient radiation dose from the X-ray source is a concern in clinical practice.
One approach to reducing radiation dose while attempting to maintain image quality is automatic exposure control (AEC). In AEC, an input radiation flux (or radiation provided by an X-ray source) is modulated during a scan to attempt to achieve a desired image quality based on pre-measurement of a patient. However, for large patients, for example, an imaging system may reach the limits of its capability, preventing the system from generating enough flux at various imaging angles, and the desired image quality may not be obtained. Low flux artifacts may be introduced in the images. Also, when using low dose scans and for certain types of measurements, photon starvation and electronic noise may dominate the measurements or otherwise adversely affect imaging.